This invention relates to water amendment technology in general. More particularly, this invention relates to methods and systems for combining a mixed component in the form of a slurry with water so as to effect remediation of the water for some utilization purpose, such as to affect soil conditions using an irrigation network.
Methods and systems are known for combining make-up water with gypsum in order to provide a slurry of predetermined initial starting concentration for the purpose of affecting soil conditions. In a typical application, a measured amount of powdered gypsum is mixed with a known volume of make-up water in order to provide a slurry of preselected initial density, depending upon the calculated soil remediation requirements, the mixture being prepared in a holding tank of special design located adjacent the inlet to an irrigation facility. The slurry mixture is then pumped from the tank to the inlet of the irrigation system, adding fresh make-up water to the tank as the slurry level in the tank drops below a predetermined minimum level. The slurry mixture in the tank is agitated continuously during the withdrawal process in order to maintain a uniform suspension of gypsum particles in water.
Known slurry make-up and distribution systems suffer from a number of disadvantages. Firstly, the agitation mechanisms used in most tanks are disposed within the tank itself, typically in a horizontal attitude. With slurry in the tank above the level of the agitator, the bearings used to mount the agitator shaft for rotation are physically contacted by the slurry mixture, which is highly abrasive to most bearing materials. As a consequence, the agitator bearings are prone to premature failure and require costly replacement. In addition, the mounting of the agitator is typically done through the end or side walls of the tank, which places large mechanical loads on these walls. The walls must thus either be reinforced at additional cost to resist these forces, or will be subject to premature failure in a form of cracking or bending.
Another disadvantage with known slurry tank configurations lies in the use of additional make-up water when the slurry level drops below a predetermined lower threshold. When additional make-up water is added to the existing slurry mixture in the tank, the density of the slurry changes. Unless this change can somehow be compensated for, the efficacy of the soil treatment is impaired and the optimum desired soil effect will never be attained. In some cases, it is possible to partially counter the effective slurry dilution by simply carrying on the slurry treatment for a longer period of time: however, at best, this adds additional water cost to the soil treatment process and, at worst, does not result in the proper amount of calcium irrigated into the soil.
Efforts to date to provide a slurry tank based soil conditioning system devoid of the above disadvantages have not met with success.